Centrifuge



Set.8

P 1964 M. A. ASNES ETAL CENTRIFUGE 3 Sheets-Sheet 1 Filed Ma 25 1962INVENT ATTonuEy p 8, 1964 M. A. ASNES ETAL 3,148,146

CENTRIFUGE Filed May 25, 1962 3 Sheets-Sheet 2 INVENTORS MARVIN A. ASNES(550/2015 GODA BY m 6. [M

ATTORNEY M. A. ASNES ETAL I NTRIF Filed May 25, 1962 VENTQ R ASNES v01265 GODA BY v United States Patent 3,148,146 CENTRIFUGE Marvin A.Asnes and George Goda, New York, N.Y.,

assignors to Clay-Adams, 130., New York, N.Y., a corporation of New YorkFiled May 25, 1962, Ser. No. 197,685 9 Claims. (Cl. 233-11) Thisinvention relates to a centrifuge and more particularly, concerns adevice used in rnicrohematocrit determinations.

An object of this invention is to provide an improved centrifugeconstruction particularly adapted to centrifuge capillary tubes inmaking microhematocrit determinations, wherein the specimen contents ofthe tubes are maintained at optimum temperature conditions during thecentrifuging operation.

As centrifuges operate at very high rates of speed and air currentsincident to the operation of the device are used for ventilating andcooling purposes, it has been found that such devices operate with arelatively high noise level which is apparently due to the air currents.

Accordingly, another object of this invention is to provide an improvedcentrifuge construction which includes means effective to markedlyreduce the noise level during operation, yet allowing optimumutilization of the incident air currents for ventilation and cooling.

Still another object of this invention is to provide in a device of thecharacter described, improved capillary tube holder means which includescover means which is conveniently in place at all times, thus avoidingthe inadvertent operation of the device without the cover means; thecover means being quickly manipulated to allow removal or insertion ofcapillary tubes in the holder; or to move the same into its operativetube enclosing position when the centrifuge is ready for operation.

Yet another object of this invention is to provide an improvedcentrifuge for hematocrit determinations wherein the head thereofincludes a tube holder and a direct reading scale which permits readingsto be taken while the tubes are still on the head; the construction ofthe device being such as to facilitate the reading of the scale.

A further object of this invention is to provide a centrifuge having animproved cover construction which is tightly sealed in its closed,latched position and is retained in its closed position after unlatchingfor a time interval after the motor has been deenergized.

Still another object of this invention is to provide an improvedcentrifuge having a head for carrying calibrated microhematocrit tubes,together with percentage scales on the head to allow for direct readingsof the centrifuged tubes, without removing the same from the head.

Other objects of this invention will in part be obvious and in parthereinafter pointed out.

In the drawing,

FIG. 1 is a vertical sectional view of a centrifuge embodying theinvention;

FIG. 2 is a top plan view thereof, with parts cut away;

FIG. 3 is a partial side elevational view thereof showing the magnifiermeans; and

FIG. 4 is a top plan view of a modified form of reader closure memberincorporating magnifier means.

Referring in detail to the drawing, designates a centrifuge embodyingthe invention. The same comprises a casing, generally indicated at 11; amotor 12 mounted ICC therein for rotating a flat disc head 13 disposedin the upper open end of the casing; and a cover 14 hingedly connectedto the rim of said casing and disposed over the head 13, when in itsclosed position.

Casing 11 comprises a lower portion 15 of truncated conical shape, theside wall 16 thereof terminating at its lower end in a recessed,peripheral edge 17 which is enclosed in a footing gasket 18. Casingportion 15 includes at its upper end a radial flange portion 19 lying ina plane slightly tilted relative to the horizontal. Ribs 20 extendradially from the inner surface of wall 16 at equiangular intervals.Side wall 16 is formed with a plurality of ventilating openings 21 atthe lower skirt portion thereof.

Motor 12 is adjustably mounted on a bracket 22 which includes anangularly disposed arm 23 disposed in a horizontal position and securedto a circular mounting plate 24, as by welding or the like. Plate 24 isresiliently mounted in the lower end of casing portion 15 by groovedrubber mountings 25 which receive cut out peripheral edge portions ofplate 24 in the grooves thereof. Mountings 25 are secured to the lowerends of ribs 20 by a screw and washer 26 threaded into bushings 27 fixedin said ribs.

As indicated in FIG. 1, bracket 22 is of an angular form so as todispose motor 12 with its longitudinal axis slightly tilted with respectto the vertical, for the purpose hereinafter appearing. The upper end ofmotor 12 projects through the opening 28 defined by flange portion 19,with the side wall of the motor in spaced relation to the edge of flangeportion 19 at said opening.

Casing 11 further includes a tilted bowl shaped upper portion 29 whichcomprises a circular side wall 30, and an angularly related bottom wallportion 31 having an inwardly extending radial flange 32 defining aperipheral edge 33 and which is secured to flange 19 of lower casingportion 15 by screws 33A. Peripheral edge 33 is coextensive with theflange edge at opening 28.

A pan 34 is mounted on upper casing portion 29, the same comprising abottom wall 35 formed with a central opening 36 to pass the upwardlyextending motor shaft 37. Pan 34 further comprises a circular side wall38 and an inverted channel shaped rim 39 extending over and secured tothe upper edge of wall 30.

The fiat disc head 13 carries on its upper face a molded plasticcapillary tube holder 40, in which are disposed capillary tubes C whichare to be centrifuged. Holder 40 comprises an open rectangular shapedframe member 41 having a central transverse flat wall portion 42 andcross rib portions 43, 43A adjacent the opposite ends thereof. Wallportion 42 is formed with parallel grooves 44 which open at the outerend edges thereof and terminate at the inner ends thereof slightly shortof a centrally located through opening 45. Rib portions 43, 43A areformed with parallel grooves 46 which are respectively aligned withgrooves 44; thus providing means for receiving the tubes C therein.

The outer end walls 47 of frame member 41 are provided with thinresilient gasket means 48 on the inner surfaces thereof for receivingthe outer ends of tubes C in abutting relation thereto. Frame member 41also comprises a circular hub portion 49 depending the undersidethereof, the same extending through a central openingin disc 13. Hubportion 49 is formed with a shouldered bore 50 which communicates with acentral opening 45 in holder wall portion 42. Scale sheets 51 showinguniformly spaced percentage lines are secured to disc 13 and 3 arelocated within the open frame ends of frame member 41. The uppersurfaces of holder wall portion 42 and ribs 43, 43A are recessedrelative to the upper frame edges, thereby providing a seat for a snuglyfitting rectangular closure member 52.

Closure member 52 is provided with a swivel nut member 53 on the centerthereof. Tilted motor shaft 37, at right angles to disc head 13,terminates in a threaded portion 37A which projects through opening 45to receive a lock unt 37B to secure disc 13 and its associated holder 40to motor shaft 37. The nut member 53 is screwed on the upper end ofthreaded shaft portion 37A; and, when only partially screwed on, saidthreaded shaft portion, allows the closure member 52 to be swivelled tothe position indicated in dotted lines, in FIG. 2, thereby exposing thegrooved portions of the holder 46 for inserting or removing tubes C. Theclosure member 52 may also be swivelled to the position indicated infull lines in FIG. 2 and the nut member 53 is then screwed down to lockthe closure member 52 to its seat on frame member 40.

Tubes C carrying blood specimens are readily mounted in the holder 40 onhead 13, to be centrifuged when motor '12 is energized for a given timeinterval. When head 13 stops rotating and closure member 52 is swivelledto its open position, the forward tilt of head 13 facilitates readingthe demarcation lines of the stratified contents of tubes C by directreference to scale sheets 51 on the head.

The cover 14 overlying the upper end of casing portion 29, is hinged toside wall by a hinge bracket 14A secured to cover 14 and pivoted on ablock 143 fixed to wall 30. Cover 14 is held in its closed position bylatch means 54 with an interposed gasket 55 on rim 39 providing a sealtherebetween.

Latch means 54 comprises an angle member 56 which is pivoted on abracket 54A fixed on the underside of a plate 57 which is secured tocover 14 and projects forwardly of the edge thereof. A vertical armportion 56A of latch member 56 is releasably engageable between a pairof laterally related opposed spring pressed detents 58 on a keeperbracket 58A secured to wall 30.

Gasket 55 comprises an inverted channel portion including peripheralflange portions 55A, 55B, and a hollow head portion 59, which abuts theunderside at the periphery of cover 14. The outer flange portion 55A ofgasket 55 is secured to the opposed portions of rim 39, as by adhesive;while the inner flange portion 55B of said gasket means is in unsecuredrelation to the opposed portions of rim 39, for the purpose hereinafterappearing.

Cover 14 is formed of transpartent plastic such as methyl methacrylateor the like to permit viewing the tube holder 40 and its closure member52 so as to make sure that the latter is in proper operative positionand to establish when disc head 13 has ceased to rotate. Cover 14 isformed with a central ventilating inlet opening 6b. Thus, when the dischead 13 is rotating at high speeds, air currents are set in motion frominlet opening 66, swirl over the top surface of disc head 13 and holder40, pass downwardly about the edge of said disc head 13 and moveradially inward between the underside of said disc head and the opposedpan wall to opening 36 therein, and thence by way of opening 33 to theinterior of lower casing portion 15, about motor 12 and out theventilating outlet openings 21; all as indicated by arrows.

Thus, heat from motor 12, as well as frictional heat developed by saidair currents, is readily dissipated and the blood specimens in tubes Care not adversely affected during centrifuging by excessive heatconditions. To further insulate tubes C from radiated and conductedheat, an insulating sheet 61 is disposed between scale sheets 51 and thedisc 13.

Also, the air current flow gives rise to excessive noise when device 10is in operation. It has been found that such noise may be markedlyreduced, when the cover 14 is tightly sealed to rim 39 of casing portion29. Thus, the unsecured flange 55B of gasket 55 is displaced, asindicated by dotted lines, in FIG. 1, towards the underside of cover 14,to attain a seal of maximum tightness uniformly about the periphery ofrim 39. Furthermore, the pressure in the upper portion of casing 11 isreduced so as to form a partial vacuum which retains cover 14 in itsclosed position for an interval after motor 12 has been deenergized.Thus, thed isc head 13, is not prematurely exposed while still rotatingunder its inertia.

A conventional timer and switch 62 with a setting knob 62A is mounted onwall 16 of casing portion 15, for suitable electrical connection tomotor 12 and current supply cord 63, to regulate the time interval ofrotation of head 13. Also, a safety switch 64 is mounted on theunderside of pan wall 35, with its spring pressed actuating pin 65projecting through an opening in wall 30 for engagement by latch member56A. Thus, in the open position of cover 14, switch 64 is effective toleave motor 12 in open circuit. Switch 64 is closed only when cover 14is in its latched position, and latch portion 56A has pressed switch pin65 inwardly.

To facilitate reading of the scale sheets 51, magnifying means 66 ismounted on the casing 11 for the convenience of the technician using thedevice. Magnifying means 66 comprises angular bracket means 67 fixed towall 30 at a point laterally adjacent latch 56 and having an upright arm68 disposed adjacent gasket 55. A swivel arm 69 is pivoted at one end tobracket arm 68, by a pivot screw 7t). Swivel arm 69 has fixed to theouter end thereof a magnifying glass 71.

The disposition of bracket means 67 and swivel arm 6? is such as tolocate magnifying glass 71 in its operative position, over a majorportion of the scale sheet 51 when the holder 40 is aligned with latchmeans 56. Of course, cover 14 is listed to its open position and closuremember 52 is swivelled when a reading is to be taken. When themagnifying glass 71 is not in use it is swung by its arm 69 to aninoperative depressed position adjacent casing portion 29.

Alternatively, as shown in FIG. 4, closure member 52 is provided withmagnifier inserts 72, 73, which are located over the scale sheets 51 fordirect reading, after the centrifuging operation is completed andwithout the need for swivelling closure 52 to its open position.

It is understood that capillary tubes C are of the calibrated type whichare filled with a predetermined quantity of blood specimen, thusallowing a uniformly spaced percentage scale to be used on scale sheets51; the lower end of the column in said tubes being registrable with the0 marking on said scale sheets to give a direct percentage reading atthe demarcation point between the blood cells and plasma. However,uncalibrated tubes may also be centrifuged in device 10, in which case,the centrifuge tubes are read on an accessory reader, not shown.

As various changes may be made in the embodiment of the invention hereinshown without departing from the spirit thereof, it is understood thatall matter herein described or illustrated is not limiting except as setforth in the appended claims.

What is claimed is:

l. A centrifuge for capillary tubes comprising a casing having a lowerportion and an upper circular portion, motor means within the lowerportion of said casing and in spaced relation to the inner surfaceportions of the side walls thereof, shaft means extending upwardly fromsaid motor means, a flat head member for carrying capillary tubes on thetop surface thereof disposed within the upper portion of said casing andoperatively engaged with said shaft means, ventilating openings in lowerportions of the side walls of said casing, a cover movably mounted onthe upper edge of the upper circular portion of said casing andoverlying said head member, said cover having a centrally locatedventilating opening, gasket means for sealing said cover to the rim ofsaid casing in the closed position thereof, pan means mounted on theupper circular portion of said casing with side and bottom wall portionsthereof respectively spaced from the peripheral edge and bottom surfaceof said head member, the bottom wall portion of said pan means beingformed with a central ventilating opening with said shaft means passingtherethrough to allow air currents incident to the rotation of said headmember and entering the opening of said cover to pass radially outwardalong the upper surface of said head member, downwardly about theperipheral edge thereof, radially inward alongthe under surface thereofand downwardly through the ventilating opening in the bottom wall ofsaid pan means about said motor means and outwardly through saidventilating openings in the lower portions of said casing to cool andventilate the interior of said casing above and below the rotating flathead member.

2. A centrifuge as in claim 1 wherein said gasket means is channelshaped in cross section, the outer flange of said gasket means beingsecured to opposed outer side wall portions of the upper portion of saidcasing, the inner flange of said gasket means being in unsecuredrelation to opposed inner side wall portions of the upper portion ofsaid casing, whereby air flow about said flat head member duringrotation thereof is effective to lift the inner flange of said gasketmeans toward the underside of said cover at the periphery thereof toincrease the sealing effect of said gasket means relative to said cover.

3. In a centrifuge for capillary tubes, a flat circular head, means forrotating said head about a vertical axis, elongated tube holder meansextending diametrically on the upper surface of said head, said holdermeans comprising grooved portions for receiving said capillary tubes, anelongated closure member for said holder means, means for swivellymounting the midportion of said closure member on said rotating meansfor movement between one position thereof angularly related to saidholder means for exposing the capillary tubes in said holder means, andanother position thereof to enclose the capillary tubes in said holdermeans, and means for locking said closure member in either positionthereof.

4. A centrifuge as in claim 3 wherein said holder means comprises arectangular shaped holder member disposed diametrically of said head andsecured thereto, said holder member comprising recessed portions forseating said closure member, screw means extending upwardly from amidportion of said holder member, a nut memher on said screw means, themidportion of said closure member being swivelly mounted on said nutmember for movement between a position overlying said holder member andseated on the recessed portions of said holder member and covering saidcapillary tubes, and a position at an angle to said holder member forexposing said capillary tubes, said nut member being in engaged relationto said screw means in either position of said cover memher.

5. A centrifuge for capillary tubes comprising a casing, motor meanswithin said casing, a flat head member within said casing and rotated bysaid motor means, capillary tube holder means on the upper surface ofsaid head member, a cover on said casing and overlying said holdermeans, said casing comprising upper and lower portions, said uppercasing portion comprising a circular side wall, a pan mounted on theside wall of said upper casing portion, said pan having a circular sidewall portion spaced from the periphery of said head member and a bottomwall spaced from the bottom wall of said head member, the bottom wall ofsaid pan being formed with an enlarged central opening to pass theupwardly extending shaft of said motor means, said head member beingsecured to said shaft and within said pan portion, a central opening insaid cover, said cover and said pan providing a path of movement for airentering said opening about the upper :and lower surface portions ofsaid head member, a major portion of said motor means being disposedwithin said lower casing portion, ventilating openings in the lower endof the side Wall of said lower casing por- 6 tion, whereby air currentsfrom said upper casing portion pass through the opening in saidpan tosaid lower casing. about said motor means and out through saidventilating openings.

6. A centrifuge as in claim 5 and further including channel shapedgasket means on the top edge of the side Wall of-said upper casingportion, the peripheral portions of said cover in the closedposition-thereof abutting said gasket means, said gasket meanscomprising an'inner flangeporti-on in unsecured relation to the innersurface of the side wall of said upper casing portion and movable in adirection to more tightly abut the underside of said cover at theperiphery thereof in response to the movement of said air currents.

7. A centrifuge for capillary tubes comprising a casing, motor meanswithin said casing, shaft means extending upwardly from said motormeans, a flat disc head secured to said shaft means, capillary tubeholder means secured to the upper surface of said head, a cover memberhinged to the rim of said casing, gasket means on the rim of saidcasing, means for latching said cover member in a closed position and insealed relation to said gasket means, ventilating outlet openings inlower portions of said casing, a ventilating inlet opening in saidcover, means for directing air entering said inlet opening in a pathabout the upper and lower surface of said disc head, downwardly aboutsaid motor means and out through said outlet openings, said gasket meansincluding movable flange portions responsive to the directed air to moveinto abutting and sealing relation to the underside of said cover memberat the periphery thereof.

8. A centrifuge comprising a casing, a motor within said casing andincluding an upwardly extending motor shaft, a disc head secured to saidshaft, capillary tube holding means on said head, said casing comprisinga lower portion and an upper bowl shaped portion, said bowl shapedportion including an annular side wall, a pan member Within said bowlshaped portion, said pan member including an annular rim portion mountedon the upper edge of the side wall of said bowl portion, said pan memberhaving a bottom wall formed with a central opening for passing saidmotor shaft, a cover hinged to said rim, latch means on said side Walland said cover for retaining said cover in its closed position, safetyswitch means for controlling said motor and located between the bowlshaped portion and said pan, said switch means being normally open andin circuit with said motor and including activating means extendingthrough said sidewall for operation by said latch means in the coverlatching position thereof to close said safety switch means.

9. A centrifuge comprising a casing having an open top portion, a dischead Within the upper end of said casing, a motor within said casing forrotating said head, capillary tube holder means on said head, a coverhinged to the open end of said casing, said cover having a centralopening therein, means for latching said cover to said casing in closedposition thereof, resilient gasket means of channel cross section on therim of said casing and in abutting relation to the underside of saidcover, said gasket means including an inner flange portion in unsecuredrelation to the inner surface of said casing opposed thereto, said innerflange portion of the gasket means being movable to abut the undersideof said cover to tightly seal the same in its latched position inresponse to the movement of air currents incident to the rotation ofsaid head.

References Cited in the file of this patent UNITED STATES PATENTS446,248 Cooper Feb. 10, 1891 495,653 Augustenborg et al Apr. 18, 18931,312,358 Robinson Aug. 5, 1919 1,648,369 Svedberg et al. Nov. 8, 1927(Other references on following page) 7 UNITED STATES PATENTS Jordan eta1. June 4, 1935 Brosnan Nov. 14, 1939 Tice Dec. 30, 1941 Barranco Aug.12, 1952 MacLeod Nov. 4, 1952 Allen et a1. Jan. 11, 1955 Jones June 19,1956 Grela et a1. Mar. 5, 1957 Weichselbaum Apr. 22, 1958 10 8 Pickelset a1 Mar. 24, 1959 Danielsson et a1. May 5, 1959 Walker Feb. 7, 1961Polanyi Nov. 21, 1961 FOREIGN PATENTS Canada May 26, 1959 Great BritainMar. 14, 1962 Germany Apr. 30, 1958 Germany July 17, 1958

1. A CENTRIFUGE FOR CAPILLARY TUBES COMPRISING A CASING HAVING A LOWERPORTION AND AN UPPER CIRCULAR PORTION, MOTOR MEANS WITHIN THE LOWERPORTION OF SAID CASING AND IN SPACED RELATION TO THE INNER SURFACEPORTIONS OF THE SIDE WALLS THEREOF, SHAFT MEANS EXTENDING UPWARDLY FROMSAID MOTOR MEANS, A FLAT HEAD MEMBER FOR CARRYING CAPILLARY TUBES ON THETOP SURFACE THEREOF DISPOSED WITHIN THE UPPER PORTON OF SAID CASING ANDOPERATIVELY ENGAGED WITH SAID SHAFT MEANS, VENTILATING OPENINGS IN LOWERPORTIONS OF THE SIDE WALLS OF SAID CASING, A COVER MOVABLY MOUNTED ONTHE UPPER EDGE OF THE UPPER CIRCULAR PORTION AND SAID CASING ANDOVERLAYING SAID HEAD MEMBER, SAID COVER HAVING A CENTRALLY LOCATEDVENTILLING OPENING, GASKET MEANS FOR SEALING SAID COVER TO THE RIM OFSAID CASING IN THE CLOSED POSITION THEREOF, PAN MEANS MOUNTED ON THEUPPER CIRCULAR PORTION OF SAID CASING WITH SIDE AND BOTTOM WALL PORTIONSTHEREOF RESPECTIVELY SPACED FROM THER PERIPHERAL EDGE AND BOTTOM SURFACEOF SAID HEAD MEMBER, THE BOTTOM WALL PORTION OF SAID PAN MEANS BEINGFORMED WITH A CENTRAL VENTILATING OPENING WITH SAID SHAFT MEANS PASSINGTHERETHROUGH TO ALLOW AIR CURRENTS INCIDENT TO THE ROTATION OF SAID HEADMEMBER AND ENTERING THE OPENING OF SAID COVER TO PASS RADIALLY OUTWARDALONG THE UPPER SURFACE OF SAID HEAD MEMBER, DOWNWARDLY ABOUT THEPERIPHERAL EDGE THEREOF, RADIALLY INWARD ALONG THE UNDER SURFACE THEREOFAND DOWNWARDLY THROUGH THE VENTILATING OPENING IN THE BOTTOM WALL OFSAID PAN MEANS ABOUT SAID MOTOR MEANS AND OUTWARDLY THROUGH SAIDVENTILATING OPENINGS IN THE LOWER PORTIONS OF SAID CASING TO COOL ANDVENTILATE THE INTERIOR OF SAID CASING ABOVE AND BELOW THE ROTATING FLATHEAD MEMBER.